During Desert Storm, there were occasional detects of the Iranian ballistic missiles by the SPY-1 radars in AEGIS Cruisers, despite the computer programs not being designed with this capability. This led to experiments and risk reduction exercises in the early 90s to understand and develop this capability.
One of the outgrowths was the Lightweight Eco-atmospheric Projectile (LEAP) experiment. This used a propulsion stack – the Terrier Missile – which could only be fired from older (pre-AEGIS) cruisers. LEAP retired significant risks, but did not achieve intercept in two attempts. The lack of intercept meant some senior leaders remained unconvinced in the feasibility of sea-based BMD
With the last of the old cruisers retired, focus shifted to the AEGIS Cruisers, and a shorter propulsion stack that could fit in the Vertical Launching System (VLS). This was called AEGIS – LEAP Intercept (ALI).
One of the key technology advancements was developing solid, miniaturized rocket motors for the third stage and kinetic warhead. With ground-based systems these could be liquid propellants, which were more characterized and understood in this usage. (Third Stage Rocket Motor – TSRM, and Solid Divert and Attitude Control System- SDACS)
In parallel with missile development was the AEGIS Weapons System (AWS) development of tracking and engagement control capability.
ALI early control test vehicle flights alternated failure with success. So a lot was riding on FM-2, the first planned intercept test – breaking the string of alternating failures, convincing senior leadership that sea-based BMD was feasible, and demonstrating the technical capability of the new motors and AWS modifications.
FM-2 was a complete success. Performance aligned almost perfectly with pre-mission prediction. More importantly, it was a huge momentum shift in the program. There were two additional successful intercept tests within the year, including the first assent-phase intercept. In August, the program received direction to deploy capability in support of Presidential Directive (NSPD-23). In October 2004, less than three years from the first intercept, the initial deployment missiles were delivered. In Jan 2005, the initial deployment configuration was successfully tested in its operational configuration called BMD 3.0.
But AEGIS BMD was not yet completely out of the woods. The initial program plan was for only a few years of missile production. The plan was to replace the SM-3 with the Kinetic Energy Interceptor (KEI). And there were occasional test failures with associated technical challenges. However, the sustained momentum and test success starting from FM-2 enabled the program to overcome these challenges.
Twenty years later, the momentum continues. Hundreds of missiles have been delivered. The SM-3 is in its fifth major configuration update (the SM-3 Blk II). Dozens of AEGIS ships have been upgraded with BMD capability, one shore site is complete and another is in development. The system capability has been demonstrated in numerous successful test events.
And USS Arleigh Burke is forward deployed with BMD capability as a key mission – relevant, capable, and on-station.
Dive deeper in the history here.